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After three executives from the company met with leaders on Capitol Hill, Sen. Mark Warner of Virginia, the ranking Democrat on the Senate Intelligence Committee, told reporters that Twitter’s presentation to investigators was “deeply disappointing.”

“Their response was frankly inadequate on almost every level,” Warner said. “I'm more than a bit surprised that anyone from the Twitter team would think that the presentation they made to the Senate staff today even began to answer the kind of questions we'd asked. So there is a lot more work they need to do.”

In a statement released after the meeting, Twitter revealed that it has identified 201 accounts linked to the Russian-generated Facebook activity that Congressional investigators say was part of a broader effort to influence the 2016 election. All those accounts, the company said, have been removed.

The company also noted that the state-owned Russian media outlet RT, or Russia Today, paid to promote 1,823 tweets that “definitely or potentially targeted the U.S. market.”

“The notion that their work was basically derivative based upon accounts that Facebook had identified showed enormous lack of understanding from the Twitter team of how serious this issue is, the threat it poses to democratic institutions,” Warner said.

Twitter isn’t off the hook just yet. Warner said today’s meeting highlights the need for an open hearing on the issue, and Rep. Adam Schiff of California, the ranking Democrat on the House Intelligence Committee, told ABC News that leaders still have a lot of unanswered questions.

“I think we’re only really beginning to understand how the Russians used social media to try to divide Americans against each other, as well as influence the outcome of the election,” Schiff said.

The Senate Intelligence Committee has invited Facebook, Twitter and Google to a public hearing on Nov. 1.

Facebook’s chief security officer Alex Stamos says most of the ads did not mention a specific presidential candidate or the election, but focused on “amplifying divisive social and political messages” on immigration, gun rights and LGBT issues. Sen. Warner, however, says it’s clear that those divisive messages were “often stories that would help one candidate and potentially hurt another,” part of a broader effort the intelligence community has determined was designed to aid Donald Trump and hurt Hillary Clinton.

Richard Clarke, a former national security official and ABC News consultant, said Russian operatives appear to have used Twitter in a similar way, promoting stories with fake identities or automated accounts, called bots.

“Twitter amplifies the stories,” Clarke said. “Twitter makes it look like there are thousands of people who agree with the point of view, when in fact it's only one troll or only one bot.”

According to Laura Rosenberger, director of the Alliance for Securing Democracy and a senior fellow at the German Marshall Fund of the United States, the Russians appear to be successfully adapting the Cold War strategies for the digital age.

“Propaganda is not new,” Rosenberger told ABC News. “What's happened is this playbook is being applied to new tools. And I think that there's no question that Vladimir Putin and the Kremlin have looked at these tools, these social media platforms, which were created to be democratizing forces … but what the Russians have done is identify weaknesses and vulnerabilities within those systems and have used it and turned them on us to attack us.”

The social media strategy, she said, is designed with broader geopolitical goals in mind.

“It's basically to blur the line between war and peace, and it's really to sow chaos in societies as a means of weakening us,” Rosenberger said. “Russia is a declining power. Their economy is getting weaker. Vladimir Putin is desperately trying to hold on to power at home. These are the ways they think they can weaken us. And it's really important for us to understand that in the Russian mindset, what they're doing here is trying to undermine the very core of our country, our democracy, and Americans simply can't allow for that to happen.”